Optical aperture device

ABSTRACT

An optical module includes an aperture device and a support structure supporting the aperture device. The aperture device defines an aperture edge and an aperture plane. The aperture edge is adapted to define a geometry of a light beam passing the aperture device along an optical axis. The support structure is adapted to hold the aperture device in a defined manner when the aperture plane is inclined with respect to a horizontal plane. A temperature distribution prevails within the aperture device and at least one of the aperture device and the support structure is adapted to maintain at least one of a relative position of the aperture edge with respect to the optical axis and a geometry of the aperture edge substantially unaltered upon an introduction of a thermal energy into the aperture device, where the thermal energy being adapted to cause an alteration in the temperature distribution.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of, and claims benefit under 35 USC120 to, international application PCT/EP2008/054433, filed Apr. 11,2008, the entire contents of which are hereby incorporated by reference.

FIELD

The disclosure relates to an optical module that may be used within anoptical device used in exposure processes, in particular inmicrolithography systems. It also relates to an optical imagingarrangement including such an optical module. It further relates to amethod of shaping a bundle of light beam used within such an opticaldevice. The disclosure may be used in the context of photolithographyprocesses for fabricating microelectronic devices, in particularsemiconductor devices, or in the context of fabricating devices, such asmasks or reticles, used during such photolithography processes.

BACKGROUND

Typically, the optical systems used in the context of fabricatingmicroelectronic devices such as semiconductor devices include aplurality of optical element modules including optical elements, such aslenses, mirrors, gratings etc., in the light path of the optical system.Those optical elements usually cooperate in an exposure process toilluminate a pattern formed on a mask, reticle or the like and totransfer an image of this pattern onto a substrate such as a wafer. Theoptical elements are usually combined in one or more functionallydistinct optical element groups that may be held within distinct opticalelement units. Further components of such optical systems are aperturedevices defining the geometry of the light beam used in the exposureprocess.

Due to the ongoing miniaturization of semiconductor devices there is adesire for enhanced resolution of the optical systems used forfabricating those semiconductor devices. One possibility to enhanceresolution of the optical systems is to reduce the wavelength of lightused in the exposure process. Thus, there currently is a strong tendencyto use light in the so-called extreme UV (EUV) range at wavelengthsbetween about 5 to 20 nm, typically at about 13 nm. However, in this EUVrange the use of refractive optical element may not be possible any moredue to the high absorption of light of such a short wavelength withinany medium, in particular within refractive optical elements.

Consequently, not only exclusively reflective optical systems are usedin such an EUV system but also a highly evacuated atmosphere has to bemaintained within the part of the light used in the exposure process.Due to the limitations in increasing the radiant power of the EUV lightfed into the optical exposure system (e.g. due to increasingly hard tohandle heating effects etc) and the extremely high sensitivity of theEUV light to absorption care has to be taken to lose as few radiantpower as possible all the way down to the substrate to be exposed.

One problem arising in this context is the loss of radiant power ataperture devices located within the path of the exposure light. In somecases, for example, it may be favorable (e.g. for a sigma variation) tohave an aperture device which is able to provide variable annularsettings. Typically, in non EUV systems, such annular settings areprovided by a solid aperture plate (e.g. made of quartz) having ashielding outer section and a shielding inner section separated by aring shaped transparent section allowing the light to pass the aperture.However, in an EUV system such an aperture plate may obviously not beused any more for reasons of absorption.

A solution could be to provide the aperture plate with correspondingcutouts in the region of the aperture such that only a few strutelements remain to radially connect the inner shielding section to theouter shielding section. However, such radial struts typically couldalso obstruct the path of the light through the aperture leading to anunwanted loss in radiant power.

A further problem arises in the context of providing varying annularsettings with such EUV systems. A variation of the annular settingtypically also includes a variation of the inner contour delimiting theannular aperture. Typically, in non EUV systems, such a variation of theannular setting is provided by exchanging the aperture plate with adifferent aperture plate providing the desired setting. However, in anEUV system (with its strict desired properties with respect to the highdegree of evacuation and the low degree of contamination of theatmosphere in the path of the exposure light) such an exchange of arather large and bulky structure can represent a considerable challengewith respect to the complexity and accuracy of the handling mechanism,the maintenance of a high-quality atmosphere (high vacuum, lowcontamination etc) and the space involved.

It will be appreciated that a solution to the above problems in an EUVsystem would also be suitable and beneficial in a conventional non EUVsystem.

SUMMARY

In some embodiments, the disclosure to, at least to some extent,overcomes the above disadvantages and to provide a simple and reliablevariation of an aperture.

In certain embodiments, the disclosure minimizes the loss in radiantpower caused by an aperture device located in the path of the exposurelight.

The disclosure is based on the teaching that it is possible to provide asimple and reliable variation of an aperture in an optical system whileminimizing the loss in radiant power by providing the possibility toindependently modify a position and/or an orientation of apertureelements of an aperture device with respect to each other in order tomodify the geometry of the aperture.

Such a configuration has the advantage that, typically, to modify thegeometry of the aperture (in contrast to the previously known exchangeof the entire aperture plate) only a part of the plurality of apertureelements has to be adjusted which is obviously leading to a reduction inthe mass to be actuated and, consequently, leading to a reduction of thecomplexity of the handling and actuating mechanism. In particular, ithas also been found that even in a case where a larger number ofhandling or actuating devices has to be used these devices may be ofless complicated design such that this advantage (less complex design)outweighs the drawbacks of having an increased number of such devices.Furthermore, the possibility to independently modify even single ones ofthe aperture elements increases the flexibility of the aperture deviceand leads to a reduction in the reaction time of the aperture device.Thus, faster setting changes may be achieved leading to an increase inthe overall productivity of the system.

Furthermore, such a configuration has the advantage that it is possibleto support these aperture elements in such a manner that (apart from theareas intentionally shielded by the aperture device to form the desiredaperture geometry) they do not obstruct the path of the exposure lightleading to a minimization of the loss in radiant power caused by theaperture device.

Thus, according to a first aspect of the disclosure there is provided anoptical module including an aperture device. The aperture deviceincludes a plurality of aperture elements defining a geometry of anaperture and including a first aperture element and a second apertureelement. The aperture device is adapted to independently modify at leastone of a position and an orientation of the first aperture element withrespect to the second aperture element to modify the geometry of theaperture.

According to a second aspect of the disclosure there is provided anoptical imaging arrangement including a mask unit adapted to receive apattern, a substrate unit adapted to receive a substrate, anillumination unit adapted to illuminate the pattern and an opticalprojection unit adapted to transfer an image of the pattern onto thesubstrate. Each of the illumination unit and the optical projection unitincludes a system of optical elements. At least one of the illuminationunit and the optical projection unit includes an optical moduleincluding an aperture device. The aperture device includes a pluralityof aperture elements defining a geometry of an aperture and including afirst aperture element and a second aperture element. The aperturedevice is adapted to independently modify at least one of a position andan orientation of the first aperture element with respect to the secondaperture element to modify the geometry of the aperture.

According to a third aspect of the disclosure there is provided a methodof shaping a bundle of light including providing a bundle of light and aplurality of aperture elements, the plurality of aperture elementsdefining a geometry of an aperture and including a first apertureelement and a second aperture element; shaping the bundle of light usingthe aperture; independently modifying at least one of a position and anorientation of the first aperture element with respect to the secondaperture element to modify the geometry of the aperture shaping thebundle of light.

As had already been mentioned above, it has been found that it ispossible to support the components of the aperture device according tothe disclosure in such a manner that they do not obstruct the path ofthe exposure light leading to a minimization of the loss in radiantpower caused by the aperture device.

Thus, according to a fourth aspect of the disclosure there is providedan optical module including an aperture device. The aperture deviceincludes a plurality of aperture elements defining a geometry of anaperture and including a first aperture element and a second apertureelement. The first aperture element, in one state of the aperturedevice, defines an inner contour of an aperture having a ring shapedgeometry. The second aperture element, in the one state of the aperturedevice, defines an outer contour of the aperture. The aperture isadapted to be passed, in the one state of the aperture device, by adefined bundle of rays of light. The first aperture element is supportedsuch that a path of the bundle of rays of light through the aperture isnot obstructed.

It will be appreciated in this context that a ring shaped geometry, inthe sense of the present disclosure, is not limited to a geometry havinga circular inner and outer contour. Rather, any geometry having anarbitrarily shaped (e.g. at least partially straight and/or at leastpartially polygonal and/or at least partially curved) inner contour andan arbitrarily shaped (e.g. at least partially straight and/or at leastpartially polygonal and/or at least partially curved) outer contour isto be understood as a ring shaped geometry in the sense of thedisclosure as long as the inner contour and the outer contour do notintersect or contact each other.

According to a fifth aspect of the disclosure there is provided anoptical imaging arrangement including a mask unit adapted to receive apattern, a substrate unit adapted to receive a substrate, anillumination unit adapted to illuminate the pattern and an opticalprojection unit adapted to transfer an image of the pattern onto thesubstrate. Each of the illumination unit and the optical projection unitincludes a system of optical elements. At least one of the illuminationunit and the optical projection unit further includes an optical module,the optical module including an aperture device including a plurality ofaperture elements. The plurality of aperture elements define a geometryof an aperture and include a first aperture element and a secondaperture element. The first aperture element, in one state of theaperture device, defines an inner contour of an aperture having a ringshaped geometry while the second aperture element, in the one state ofthe aperture device, defines an outer contour of the aperture. Theaperture is adapted to be passed, in the one state of the aperturedevice, by a defined bundle of rays of light. The first aperture elementis supported such that a path of the bundle of rays of light through theaperture is not obstructed.

According to a sixth aspect of the disclosure there is provided anoptical module including an aperture device including a movable apertureelement. The movable aperture element defines a geometry of an apertureand is movable from a first state to a second state. The movableaperture element in adapted to shield, in a first state, at least a partof an optically used surface of an optical element located adjacent tothe aperture device from incident light propagating along a line ofpropagation. The movable aperture element has a plurality of recesses,at least one of the recesses, in the second state, being located suchthat the incident light propagating along the line of propagation hitsthe part of the optically used surface shielded in the first state.

All combinations of the features disclosed, whether explicitly recitedin the claims or not, are within the scope of the disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

Further aspects and embodiments of the disclosure will become apparentfrom the dependent claims and the following description of preferredembodiments which refers to the appended figures, in which:

FIG. 1 is a schematic representation of a preferred embodiment of anoptical imaging arrangement according to the disclosure which includes apreferred embodiment of an optical module according to the disclosureand with which preferred embodiments of methods according to thedisclosure may be executed;

FIG. 2 is a schematic sectional representation of an optical moduleaccording to the disclosure being a part of the optical imagingarrangement of FIG. 1 (along line II-II of FIG. 3);

FIG. 3 is a schematic top view of the optical module of FIG. 2 alongarrow III of FIG. 2;

FIG. 4 is a block diagram of a preferred embodiment of a method ofshaping a bundle of light which may be executed with the optical imagingarrangement of FIG. 1.

FIG. 5 is a schematic top view of a further preferred embodiment of anoptical module according to the disclosure;

FIG. 6 is a schematic sectional view (along line VI-VI of FIG. 7) of apart of a further preferred embodiment of an optical module according tothe disclosure;

FIG. 7 is a schematic top view of a part of the embodiment of FIG. 6(seen along arrow VII of FIG. 6);

FIG. 8 is a schematic sectional view of a part of a further preferredembodiment of an optical module according to the disclosure;

FIG. 9 is a schematic top view of a part of a further preferredembodiment of an optical module according to the disclosure in a firststate;

FIG. 10 is a schematic top view of the optical module of FIG. 9 in asecond state;

FIG. 11 is a schematic top view of the optical module of FIG. 9 in athird state;

FIG. 12 is a schematic top view of a further preferred embodiment of anoptical module according to the disclosure.

DETAILED DESCRIPTION OF THE DISCLOSURE First embodiment

In the following, a first preferred embodiment of an optical imagingarrangement 101 according to the disclosure will be described withreference to FIGS. 1 to 4.

FIG. 1 is a schematic and not-to-scale representation of the opticalimaging arrangement in the form of an optical exposure apparatus 101used in a microlithography process during manufacture of semiconductordevices. The optical exposure apparatus 101 includes a first opticaldevice in the form of an illumination unit 102 and a second opticaldevice in the form of an optical projection unit 103 adapted totransfer, in an exposure process, an image of a pattern formed on a mask104.1 of a mask unit 104 onto a substrate 105.1 of a substrate unit 105.To this end, the illumination unit 102 illuminates the mask 104.1. Theoptical projection unit 103 receives the light coming from the mask104.1 and projects the image of the pattern formed on the mask 104.1onto the substrate 105.1, e.g. a wafer or the like.

The illumination unit 102 includes an optical element system 106 (onlyshown in a highly simplified manner in FIG. 1) including a plurality ofoptical element units such as optical element unit 106.1. As will beexplained in further detail below, the optical element unit 106.1 isformed as a preferred embodiment of an optical module according to thedisclosure. The optical projection unit 103 includes a further opticalelement system 107 including a plurality of optical element units 107.1.The optical element units of the optical element systems 106 and 107 arealigned along a folded optical axis 101.1 of the optical exposureapparatus 101.

In the embodiment shown, the optical exposure apparatus works with lightin the EUV range at a wavelength between 5 nm to 20 nm, more preciselyat a wavelength of 13 nm. Thus, the optical elements used within theillumination unit 102 and the optical projection unit 103 areexclusively reflective optical elements. However, it will be appreciatedthat, with other embodiments of the disclosure working at differentwavelengths, any type of optical element (refractive, reflective ordiffractive) may be used alone or in an arbitrary combination. Theoptical element system 107 may include a further optical module 108according to the disclosure.

As can be seen from FIGS. 2 and 3, the optical module 106.1 includes anaperture device in the form of a aperture stop 109, a support structure110 supporting the aperture stop 109 and an optical element 111 alsosupported by the support structure 110.

The optical element 111 is a reflective optical element, i.e. a mirror,formed by a plurality of separate mirror elements 111.1 each having areflective partial surface 111.2 facing away from the support structure110. The reflective partial surfaces 111.2 together form the reflectivesurface 111.3 of the optical element 111.

The mirror elements 111.1 are separately supported on the supportstructure 110 by any suitable mechanism (not shown in further detail).However, it will be appreciated that, with other embodiments of thedisclosure, a monolithic optical element of any suitable type and designmay be chosen as well.

The support structure 110, in the embodiment shown, is a simple plateshaped support which itself is supported (by a mechanism not shown infurther detail) by the housing 102.1 of the illumination unit 102.However, it will be appreciated that, with other embodiments of thedisclosure, the support structure may be of any suitable type and moreor less sophisticated design. In particular, sophisticated coolingdevices and/or actuating devices etc may be integrated into the supportstructure.

The aperture stop 109, in the state shown in FIGS. 2 and 3, defines anaperture 109.1 having a ring shaped geometry which is concentric to theoptical axis 101.1. However, it will be appreciated that, with otherembodiments of the disclosure, any other desired relative position ofthe aperture with respect to the optical axis may be chosen depending onthe desired properties of the actual optical system.

The aperture stop 109 includes two separate aperture elements, namely aninner first aperture element of 109.2 and an outer second apertureelement 109.3. The first aperture element 109.2 defines the innercontour 109.4 of the ring shaped aperture 109.1 while the secondaperture element 109.3 defines the outer contour 109.5 of the ringshaped aperture 109.1.

The first aperture element 109.2 is a simple planar element of circularshape shielding a part of the reflective surface 111.3 of the mirror 111from light incident along a line of propagation, e.g. along the opticalaxis 101.2. More precisely, the first aperture element 109.2 shields thepart of the reflective surface 111.3 that is formed by the mirrorelements 111.1 spanned by the first aperture element 109.2.

The second aperture element 109.3 includes a simple ring shapedshielding part also shielding a part of the reflective surface 111.3 ofthe mirror 111 from light incident along a line of propagation, e.g.along the optical axis 101.2. More precisely, the second apertureelement 109.3 shields the part of the reflective surface 111.3 that isformed by the mirror elements 111.1 spanned by the second apertureelement 109.3.

It will be appreciated that the aperture 109.1 formed by the firstaperture element 109.2 and the second aperture element 109.3 may haveany desired annular geometry. In particular, the inner contour of 109.4and/or the outer contour 109.5 may have any desired (and least sectionwise curved and/or polygonal) geometry. For example, each one of thesecontour is does not necessarily have to be of circular shape.Furthermore, the inner contour of 109.4 and the outer contour 109.5 donot necessarily have to be concentric (i.e. they do not necessarily haveto have coinciding area centers of gravity).

The first aperture element 109.2 is supported on the support structure110 via a first support device 109.6 including a plurality of firstsupport elements 109.7 and a plurality of first locking devices 109.8.Each of the first support elements 109.7 is formed as an elongated strutextending (in a direction parallel to the optical axis 101.1) within alateral gap formed between adjacent mirror elements 111.1.

Each first support element 109.7 co-operates with an associated firstlocking device 109.8, each first locking device 109.8 releaseablylocking the associated first support element 109.7 in place in at leastone degree of freedom (DOF). Different first locking devices 109.8restrict different degrees of freedom such that the first apertureelement 109.2 is safely held in place in all six degrees of freedom.However, it will be appreciated that, with other embodiments of thedisclosure, restriction in a different number of degrees of freedom mayalso be provided.

The second aperture element 109.3 is supported on the support structure110 via a second support device 109.9 including a plurality of secondsupport elements 109.10 and a plurality of second locking devices 109.11distributed at the outer circumference of the support structure 110 andthe mirror 111, respectively. Each of the second support elements 109.10is formed as an elongated strut extending (in a direction parallel tothe optical axis 101.1).

Each second support element 109.10 co-operates with an associated secondlocking device 109.11, each second locking device 109.11 releaseablylocking the associated second support element 109.10 in place in atleast one degree of freedom (DOF). Different second locking devices109.10 restrict different degrees of freedom such that the secondaperture element 109.3 is safely held in place in all six degrees offreedom. However, it will be appreciated that, with other embodiments ofthe disclosure, restriction in a different number of degrees of freedommay also be provided.

The first locking devices 109.8 and the second locking devices 109.11may be of any suitable type and design to provide the desiredrestriction in the desired number of degrees of freedom. In particular,the respective locking device 109.8, 109.11 may use any suitable workingprinciple providing a releasable connection between the support element109.7 and the support structure 110. For example, mechanical workingprinciples, electric working principles, magnetic working principles,fluidic working principles etc and arbitrary combinations thereof may beused.

Locking and release of the respective locking device 109.8 and 109.11may be actively controlled via a control device 109.12 connected to eachone of the respective locking devices 109.8 and 109.11. For example, afluidic working principle, more precisely a pneumatic working principlemay be used where the control device 109.12 establishes a negativepressure at a location of contact between the locking device 109.8,109.11 and the associated support element 109.7, 109.10 providing theholding forces to hold the respective aperture element 109.2 and 109.3in place.

However, with other embodiments of the disclosure, a self retainingmechanical solution may be chosen where a frictional and/or positiveconnection is provided between the locking device and the associatedsupport element. In the most simple case a simple snap on connection maybe used. However, preferably, some kind of actuator or the like isprovided for the releasing action. This has the advantage that thesupport device does not have to be permanently energized (thus avoidingheating problems etc).

It will be further appreciated that, with other embodiments of thedisclosure, such separate locking devices may (at least partially) beomitted and the respective aperture element may be held in place by thegravitational force acting on it and the frictional force resultingtherefrom at the contact location between the respective support elementand the supporting structure.

The releasable and separate support of the respective aperture element109.2 and 109.3 on the support structure 110 has several advantages. Onethe one hand, due to the separate support of the respective apertureelement 109.2 and 109.3 a design is achieved where none of the supportdevices 109.6 and 109.9 used to support the respective aperture element109.2 and 109.3 obstructs the path of the exposure light provided by thelight source of the illumination unit 102 through the aperture device109. Consequently, no loss in radiant energy is caused by the support ofthe aperture elements 109.2 and 109.3.

In this case, in other words, a defined bundle of rays of lightcorresponding to the geometry of the aperture 109.1 is intended to passthe aperture 109.1 in a defined direction of radiation (e.g. parallel tothe optical axis 101.1) with a defined average radiant power per areaP_(rel,av) in this direction of radiation. Furthermore, the innercontour 109.4 and the outer contour 109.5, in a plane perpendicular tothis direction of radiation, define a ring shaped surface having adefined area A. The support of the aperture elements 109.2 and 109.3 asoutlined above has the advantage that the radiant power P of thisdefined bundle of rays of light after passing the aperture 109.1 in thisdirection of radiation corresponds to the product of the average radiantpower per area P_(rel,av) and the defined area A of the ring shapedsurface, i.e. it calculates as:

P=P _(rel,av) ·A.  (1)

In other words, as mentioned above, no undesired loss in radiant poweris caused by the support of the components of the aperture stop 109 inthe area of the aperture 109.1.

Furthermore, the separate releasable support of the respective apertureelement 109.2 and 109.3 allows for an easy change in the geometry of theaperture 109.1. More precisely, each one of the first aperture element109.2 and the second aperture element 109.3 may be easily exchanged byanother suitable aperture element having a different geometry (e.g.provided from a corresponding magazine including a plurality of suchaperture elements), thus modifying at least one of the geometry and theorientation of the respective aperture element. This allows an easy andfast modification of the geometry of the aperture 109.1 as it isindicated in FIG. 3 by the dashed contours 112.1 (e.g. resulting from anexchange of the inner aperture element 109.2) and 112.2 (e.g. resultingfrom an exchange of the outer aperture element 109.3).

In particular, contrary to the known designs with a single solidaperture plate (as it has been outlined above) by far lighter components(namely the first and second aperture element 109.2 and 109.3) have tobe moved for changing the geometry of the aperture 109.1. Thus, thehandling mechanism for exchanging the aperture elements 109.2 and 109.3(not shown in further detail in FIGS. 1 to 3, e.g. a movable arm with agrasping mechanism for grasping the respective aperture element) may beof less complex and bulky design. This leads to a reduction in thehandling and contamination risk, a less complex control and easierintegration into the optical imaging apparatus 101.

Such handling mechanisms may be of any desired design and may execute anarbitrarly complex handling motion in space (e.g. an arbitrarycombination of translatory and rotational motions). For example, theremay be provided one single movable arm with a grasping mechanism whichsubsequently places the respective aperture element at the desiredlocation. However, with other embodiments of the disclosure, it may alsobe provided that the handling mechanism places all the aperture elementsto be placed at a time. Furthermore, separate handling mechanisms may beprovided for the separate aperture elements. In particular, it may beprovided that the separate aperture elements (e.g. the inner apertureelement and the outer aperture element) are taken from separate storagedevices.

It will be appreciated that the light source of the illumination unit102, in the embodiment shown in FIGS. 1 to 3, provides a defined bundleof rays of light including a plurality of spatially confined sub-bundlesseparated by a non-irradiated area not being irradiated by the bundle ofrays of light as it is difficult for so-called LPP (laser producedplasma) EUV light sources, for example. In the embodiment shown, amirror element 111.1 is associated to each one of these sub-bundles.

However, it will be appreciated that, with other embodiments of thedisclosure, a light source may be used providing a continuous bundle ofrays of light not being separated into such individual spatiallyconfined sub-bundles separated by non-irradiated areas. In this case, itis also possible that the optical element is a monolithic element (i.e.not composed of a plurality of spatially separated sub-elements) andthat the respective aperture element, in particular the inner apertureelement is directly supported on the optically used surface of theoptical element.

It will be appreciated that, during an exposure process the aperturestop 109 absorbs a considerable amount of radiation energy provided bythe light incident on the aperture stop 109. As a consequence, thetemperature distribution within the aperture stop 109 successivelychanges due to the thermal energy introduced into the aperture stop 109via the absorbed radiation energy. Typically, the part of the aperturestop 109 exposed to the incident light experiences a considerableincrease in its temperature. This temperature increase leads to athermal expansion of at least parts of the aperture stop 109 which(unless counteracted) in turn might lead to an undesired alteration ofthe relative position between the aperture edge 109.1 and the opticalaxis 101.1.

Thus, with preferred embodiments of the disclosure, passive and/oractive thermal stabilization of the support structure 110 and therespective aperture element 109.2 and 109.3 may be provided (e.g.passive tempering/cooling elements such as tempering/cooling ribs etc oractive tempering/cooling devices such as a tempering/cooling circuitetc).

For example, an active thermal balancing device in the form of an activetemperature control circuit of the aperture stop 109 may be provided.Such an active temperature control circuit may for example use a fluidiccoolant or electric cooling elements such as Peltier elements etc.Preferably, the temperature control circuit provides the temperaturecontrol via the support structure of 110 and the support devices 109.6and 109.9.

Furthermore, it will be appreciated that, with other embodiments of thedisclosure, the aperture stop 109 itself may be designed such that itprevents or reduces an alteration in the relative position of theaperture 109.1 with respect to the optical axis 101.1. For example, theaperture stop 109 may be made of a material having a near zerocoefficient of thermal expansion (CTE), thus largely avoiding thermalexpansion of the aperture stop 109. Such materials are for exampleInvar, Zerodur, etc.

Furthermore, it will be appreciated that, with other embodiments of thedisclosure, the aperture stop itself may be designed such that itprevents or reduces an alteration in the relative position of theaperture 109.1 with respect to the optical axis 101.1 by avoiding or atleast reducing a change in the temperature distribution within theaperture stop 109.

To this end, for example, passive thermal balancing device may be usedproviding improved heat removal from the aperture stop 109. Such apassive mechanism may be, for example, a suitable surface of theaperture stop 109 providing increased heat removal by providingincreased radiation. Preferably such increased radiation is provided asdirected radiation in order to avoid undesired heating of othertemperature sensitive components of the imaging device 101.

With the optical exposure apparatus 101 of FIG. 1 a preferred embodimentof a method of shaping a light beam according to the disclosure may beexecuted as it will be described in the following with reference toFIGS. 1 to 4.

In a step 112.1, the components of the optical exposure device 101 asthey have been described above are provided and put into a spatialrelation to provide the configuration as it has been described in thecontext of FIGS. 1 to 3.

In a step 112.2, the optical exposure device 101 is used to expose oneor several images of the pattern formed on the mask 104.1 onto thesubstrate 105.1 as it has been described above. During this step theaperture stop 109 shapes the bundle of rays of light passing it alongthe optical axis 101.1.

In a step 112.3, at least one of the inner aperture element 109.2 andthe outer aperture element 109.3 is exchanged by another apertureelement having a different geometry and/or orientation such that thegeometry of the aperture 109.1 is changed. This change in the geometryof the aperture 109.1 leads to a different shape of the bundle of raysof light passing the aperture stop 109 as it has been outlined above.

Second Embodiment

In the following, a second embodiment of the optical module 206.1according to the disclosure will be described with reference to FIG. 5.The optical module 206.1 in its basic design and functionality largelycorresponds to the optical module 106.1 and may replace the opticalmodule 106.1 in the optical imaging device 101 of FIG. 1. In particular,with the optical module 206.1 the method of shaping a bundle of rays oflight as it has been described above in the context of the firstembodiment (FIG. 4) may be executed. Thus, it is here mainly referred tothe explanations given above and only the differences with respect tothe optical module 106.1 will be explained in further detail. Inparticular, similar parts are given the same reference numeral raised bythe amount 100 and (unless explicitly described in the following) inrespect to these parts reference is made to the explanations given abovein the context of the first embodiment.

The only difference with respect to the optical module 106.1 lies withinthe fact that the inner aperture element 209.2 of the aperture stop 209is not directly supported on the support structure 210. Instead, theinner aperture element 209.2 is supported by the outer aperture element209.3 via a plurality of strut elements 209.13 (here: three strutelements 209.13) extending in a radial direction in the plane of mainextension defined by the aperture stop 209.

As can be seen from FIG. 5, the respective strut element 209.13 isformed by a plurality of honeycomb shaped elements 209.14 arranged andconnected to each other in such a manner that they do not interfere withthe sub-bundles of the bundle of rays of light provided by the lightsource of the illumination unit 102. More precisely, the wall sectionsof the honeycomb elements 209.14 are arranged such that they extend inthe non-irradiated area located between the spatially confinedsub-bundles of the bundle of rays light provided by the light source ofthe illumination unit 102. Thus, the strut elements 209.13 do notobstruct the path of the exposure light on its way through the aperturestop and, consequently, the support of the aperture elements 209.2 and209.3 does not cause any loss in the radiant power.

The strut elements 209.13 are releaseably connected to the inneraperture element 209.2 and/or the outer aperture element 209.3. Thus,for example, the geometry and/or orientation of the aperture 209.1 maybe easily modified (in the step 112.3 of FIG. 3) by releasing theconnection between the strut elements 209.13 and the inner apertureelement 209.2 and/or the outer aperture element 209.3 and by exchangingthe inner aperture element 209.2 (eventually together with the strutelements 209.13) by another inner aperture element of different geometryand/or orientation.

It will be appreciated that the wall sections of the honeycomb elements209.14 have a suitable defined dimension along the optical axis 101.1 inorder to provide a sufficiently rigid support of the inner apertureelement 209.2 along the optical axis 101.1.

It will be further appreciated that a different number of strut elementsmay be provided. Furthermore, the wall elements of the strut elementsmay be of any other suitable (at least section wise curved and/orangled) design as long as the do not interfere with the respectiveadjacent sub-bundels of rays of light.

It will be further appreciated that, with other embodiments of thedisclosure, the inner aperture element and the outer aperture elementmay be connected via the strut elements (not interfering with therespective adjacent sub-bundels of rays of light) in a non-releasablemanner (e.g. in a monolithic manner) such that the inner apertureelement and the outer aperture element are exchanged together to modifythe geometry of the aperture.

Third Embodiment

In the following, a third embodiment of the optical module 306.1according to the disclosure will be described with reference to FIG. 6and FIG. 7 (showing a schematic top view of a part of the optical module306.1 corresponding to the section confined by the contour 112.1 in FIG.3). The optical module 306.1 in its basic design and functionalitylargely corresponds to the optical module 106.1 and may replace theoptical module 106.1 in the optical imaging device 101 of FIG. 1. Inparticular, with the optical module 306.1 the method of shaping a bundleof rays of light as it has been described above in the context of thefirst embodiment (FIG. 4) may be executed. Thus, it is here mainlyreferred to the explanations given above and only the differences withrespect to the optical module 106.1 will be explained in further detail.In particular, similar parts are given the same reference numeral raisedby the amount 200 and (unless explicitly described in the following) inrespect to these parts reference is made to the explanations given abovein the context of the first embodiment.

The difference with respect to the optical module 106.1 lies within thefact that the inner contour 309.4 of the aperture 309.1 is defined by aplurality of mutually overlapping first aperture elements 309.2. Eachfirst aperture element 309.2 is a umbrella-like element that may beselectively transferred from a first state to a second state and back.

As can be seen from FIG. 6 (being a schematic sectional partial view inthe region of one first aperture element 309.2) each umbrella-likeaperture element 309.2 includes a plurality of ribs 309.15interconnected by a thin and flexible sheet element 309.16. The ribs309.15 are pivotably connected to a central rod 309.17 which in turn isconnected to an actuating device 309.18 selectively moving the centralrod 309.17 back and forth in the direction of arrow 313 under thecontrol of the control device 309.19. The central rod 309.17 is arrangedwithin a tubular receptacle 309.20 provided in the support structure 310in a gap between adjacent mirror elements 111.1.

In the first state, each aperture element 309.2 is in an extended statewhere the ribs 309.15 are located outside the receptacle 309.20. In thisfirst state, the ribs 309.15 (e.g. under the influence of spring forceof a spring element not shown in further detail in FIGS. 6 and 7) arepivoted into a radial orientation such that the aperture element 309.2unfolds in the manner of an umbrella (thereby placing the sheet element309.16 under tension) and forms a substantially planar element ofcircular shape shielding a part of the reflective surface 111.3 of themirror 111 from light incident along a line of propagation, e.g. alongthe optical axis 101.2. More precisely, the aperture element 309.2 inthis first state mainly extends a plane substantially perpendicular tothe optical axis 101.1 and shields the part of the reflective surface111.3 that is formed by the mirror elements 111.1 spanned by the firstaperture element 309.2.

In the second state, each aperture element 309.2 is in a retracted statewhere the ribs 309.15 (together with the sheet element 309.16) arefolded back and retracted into the receptacle 309.20 (see dashed contour314 of FIG. 6). In this second state, the aperture element 309.2 givesway such that it does not shield any of the mirror elements fromincident light.

In order to modify the geometry of the aperture 309.1 (in the step 112.3of FIG. 4), under the control of the control device 309.19, a suitablenumber of first aperture elements 309.2 is successively unfolded(preferably one after the other), i.e. transferred from its second stateto its first state, in order to provide a mutually overlappingarrangement as it is shown in FIG. 7, for example. If a differentgeometry of the aperture 309.1 is to be provided, another number offirst aperture elements 309.2 (eventually having a different location)is brought into the first state.

It will be appreciated that the first aperture elements 309.2 may bedistributed over the entire optical module 306.1 such that virtually anydesired geometry of the aperture 309.1 may be achieved. In particular,arbitrary circular or annular configurations of the aperture 309.1 maybe achieved where the outer contour of the aperture is defined by therespective aperture elements 309.2.

It will be appreciated that, with this embodiment as well, the supportto the respective aperture element 309.2 does not obstruct the path ofthe exposure light through the aperture 309.1 such that no loss inradiant power is caused by the support to the respective apertureelement 309.2. Furthermore, this embodiment provides a rather simplepossibility to selectively modify the geometry of the aperture withouthaving to move large masses. This solution provides a high flexibilityand very short reaction times for changes in the setting of theaperture. Furthermore, only very little space is involved to implementthis solution.

It will be further appreciated that, with other embodiments of thedisclosure, any other configuration may be chosen providing such aselectively folding and unfolding design. In particular, the flexiblesheet element may be replaced by a plurality of substantially rigidelements each one connected to one of the ribs. In this case, of course,a suitable shape of the receptacle has to be chosen.

Fourth Embodiment

In the following, a fourth embodiment of the optical module 406.1according to the disclosure will be described with reference to FIG. 8.The optical module in its basic design and functionality largelycorresponds to the optical module 106.1 and may replace the opticalmodule 106.1 in the optical imaging device 101 of FIG. 1. In particular,with the optical module 406.1 the method of shaping a bundle of rays oflight as it has been described above in the context of the firstembodiment (FIG. 4) may be executed. Thus, it is here mainly referred tothe explanations given above and only the differences with respect tothe optical module 106.1 will be explained in further detail. Inparticular, similar parts are given the same reference numeral raised bythe amount 300 and (unless explicitly described in the following) inrespect to these parts reference is made to the explanations given abovein the context of the first embodiment.

The difference with respect to the optical module 106.1 lies within thefact that the aperture stop 409 is made of a plurality of apertureelements 409.2. A defined number of aperture elements 409.2 isassociated to one of a plurality of the mirror elements 111.1 of themirror 111. Preferably, a defined number of aperture elements 409.2 isassociated to each one of the mirror elements 111.1.

As can be seen from FIG. 8 (being a schematic partial sectional view inthe region of two mirror elements 111.1) aperture element 409.2 isformed by an elongated element partially extending in the gap betweentwo adjacent mirror elements 111.1 and having an active bending section409.21 which may be transferred, under the control of a control unit409.19 from a bent (first) state to a straight (second) state. To thisend, the bending section 409.21 may be formed from any material ormaterial combination providing such an active control of its geometry.For example, a shape memory or other active material or materialcombination may be used which is transferred between the first state andthe second state depending on an external field (e.g. a thermal fieldand/or an electric field and/or a magnetic field) established in theregion of the bending section 409.21.

In the first state, each aperture element 409.2 is in a bent state wherethe free end part 409.22 of the aperture element 409.2 is shielding apart of the reflective surface 111.2 of the associated mirror element111.1 from light incident along a line of propagation, e.g. along theoptical axis 101.2. More precisely, the free end part 409.22 in thisfirst state mainly extends a plane substantially perpendicular to theoptical axis 101.1 and shields a part of the reflective surface 111.3that is formed by the respective mirror elements 111.1 spanned by thefree end part 409.22. The number and shape of the aperture elements409.2 associated to the respective mirror element 111.1 is selected suchthat the reflective surface 111.2 of the respective mirror element 111.1is fully shielded in the first state of the aperture elements 409.2.

In the second state, each aperture element 409.2 is in a straightenedstate where the bending section 409.21 is straightened (see the dashedcontour 415 of FIG. 8). In this second state, the aperture element 309.2gives way such that it does not shield the mirror element 111.1 fromincident light along the line of propagation.

In order to modify the geometry of the aperture 409.1 (in the step 112.3of FIG. 4), under the control of the control device 409.19, a suitablenumber of first aperture elements 409.2 is selectively transferred fromits second state to its first state, in order to selectively shield therespective mirror element 111.1 from incident light.

It will be appreciated that the aperture elements 409.2 may bedistributed over the entire optical module 406.1 such that virtually anydesired geometry of the aperture 409.1 may be achieved. In particular,arbitrary circular or annular configurations of the aperture 409.1 maybe achieved where the outer contour of the aperture is defined by therespective aperture elements 409.2.

It will be further appreciated that, with other embodiments of thedisclosure, the aperture elements may be entirely formed by the bendingsection, i.e. deform over their entire length. Furthermore, eachaperture element may include a plurality of such actively (eventuallyselectively) deformable sections in order to be able to provide adesired trajectory of the deformation.

It will be appreciated that, with this embodiment as well, the supportto the respective aperture element 409.2 does not obstruct the path ofthe exposure light through the aperture 409.1 such that no loss inradiant power is caused by the support to the respective apertureelement 409.2. Furthermore, this embodiment provides a rather simplepossibility to selectively modify the geometry of the aperture withouthaving to move large masses. This solution provides a high flexibilityand very short reaction times for changes in the setting of the aperturesince all mirror elements 111.1 desired to be shielded may be shieldedat a time. Furthermore, only very little space is involved to implementthis solution.

Fifth Embodiment

In the following, a fifth embodiment of an optical module 506.1according to the disclosure will be described with reference to FIGS. 9to 11. The optical module 506.1 in its basic design and functionalitylargely corresponds to the optical module 106.1 and may replace theoptical module 106.1 in the optical imaging device 101 of FIG. 1. Inparticular, with the optical module 506.1 the method of shaping a bundleof rays of light as it has been described above in the context of thefirst embodiment (FIG. 4) may be executed. Thus, it is here mainlyreferred to the explanations given above and only the differences withrespect to the optical module 106.1 will be explained in further detail.In particular, similar parts are given the same reference numeral raisedby the amount 400 and (unless explicitly described in the following) inrespect to these parts reference is made to the explanations given abovein the context of the first embodiment.

As may be seen from FIG. 9 (being a highly schematic top view of theoptical module 506.1 similar to the view of FIG. 3) the aperture stop509 is formed by a planar, substantially plate shaped aperture element509.2 which is rotatably supported on the support structure 110. Theaperture element 509.2 includes a plurality of recesses in the form ofslots 509.23 extending through the aperture element 509.2 and forming apassageway for light passing the aperture stop 509. Each of the slots509.23 is associated to one of the spatially confined sub-bundles 516.1of the bundle 516 of rays of light provided by the light source of theillumination unit 102.1. The sub-bundles 516.1 are evenly distributedand separated by non-irradiated areas as it has been described above.

In the circumferential direction 517 of the aperture stop, the slotshave an arcuate design which is substantially concentric to the axis ofrotation of the aperture element 509.2. This axis of rotation of theaperture element 509.2 may coincide with the optical axis 101.1.However, with other embodiments of the disclosure, any other suitableand desired orientation of the axis of rotation of the aperture elementwith respect to the optical axis 101.1 may be chosen.

The aperture element 509.2, under the control of a control unit 509.19,may be driven (clockwise and counterclockwise) along the circumferentialdirection 517 via a drive unit 509.24 connected to the control unit509.19 and supported on the support structure 110. In the state shown inFIG. 9 the slots 509.23 of the aperture element 509.2 are arranged suchthat none of the sub-bundles 516.1 is blocked by the aperture element509.2, i.e. all the sub-bundles 516.1 of the bundle 516 can pass theaperture element 509.2 in their direction of propagation.

In the state shown in FIG. 10 the aperture element 509.2 has beenrotated (with respect to the state shown in FIG. 9) counterclockwise bya given angle α. In this state the slots 509.23 arranged on the innertwo slot circles 509.25 and 509.26 are located such that the associatedsub-bundles 516.1 may not pass them any more while the other slots509.23 arranged on the outer three slot circles 509.27 to 509.29 arelocated such that the associated sub-bundles 516.1 may still pass them.Thus, the aperture 509.1 provided by the aperture element 509.2 has anannular shape in this state shown in FIG. 10.

In other words, in this state, the part of the aperture element 509.2located in the region of the inner two slot circles 509.25 and 509.26may be considered as an inner aperture element which is supported viathe (monolithically connected) part of the aperture element 509.2located in the region of the outer three slot circles 509.27 to 509.29on the part forming the outer circumference of the aperture element509.2.

In the state shown in FIG. 11 the aperture element 509.2 has beenrotated (with respect to the state shown in FIG. 9) clockwise by a givenangle β. In this state the slots 509.23 arranged on the outer two slotcircles 509.28 and 509.29 are located such that the associatedsub-bundles 516.1 may not pass them any more while the other slots509.23 arranged on the inner three slot circles 509.25 to 509.27 arelocated such that the associated sub-bundles 516.1 may still pass them.Thus, the aperture 509.1 provided by the aperture element 509.2 has acircular shape in this state shown in FIG. 11.

It will be appreciated that, with this embodiment as well, in therespective state, the support to the respective parts of the apertureelement 509.2 does not obstruct the path of the exposure light throughthe aperture 509.1 such that no loss in radiant power is caused by thesupport to the respective parts of the aperture element 509.2.

Furthermore, this embodiment provides a very simple possibility toselectively modify the geometry of the aperture without having to movelarge masses along a complicated trajectory. Instead, only a simplerotation is involved to modify the geometry of the aperture 509.1. Thissolution provides very short reaction times for changes in the settingof the aperture since only a small angle of rotation may be sufficientto provide a change to the desired setting.

It will be further appreciated that the aperture slots 509.23 may bearranged such that they provide virtually any desired geometry of theaperture 509.1. Furthermore, it will be appreciated that the apertureelement 509.2 may be used in connection with any desired opticalelement. In other words, this solution is not limited to animplementation in connection with the segmented mirror 111 as it hasbeen described above. Rather any type of optical element may beassociated to the aperture element 509.2.

Furthermore, since the aperture element 509.2 does not necessitate anysupport apart from a support at its outer circumference, it is notnecessary to provide a close spatial relation between the apertureelement 509.2 and an optical element. Rather, the optical module 506.1may only include the aperture element 509.2 and no optical elementsupported by the support structure of the aperture element 509.2. Inthis case, obviously, the support structure of the aperture element509.2 may have an annular design not obstructing the part of the lightpassing the aperture element 509.2. In particular, the aperture element509.21 may for example be used in the optical module 108 of the opticalprojection unit 103 of FIG. 1.

Sixth Embodiment

In the following, a sixth embodiment of an optical module 606.1according to the disclosure will be described with reference to FIG. 12.The optical module 606.1 in its basic design and functionality largelycorresponds to the optical module 506.1 and may replace the opticalmodule 106.1 in the optical imaging device 101 of FIG. 1. In particular,with the optical module 606.1 the method of shaping a bundle of rays oflight as it has been described above in the context of the firstembodiment (FIG. 4) may be executed. Thus, it is here mainly referred tothe explanations given above and only the differences with respect tothe optical module 506.1 will be explained in further detail. Inparticular, similar parts are given the same reference numeral raised bythe amount 100 and (unless explicitly described in the following) inrespect to these parts reference is made to the explanations given abovein the context of the first embodiment.

As may be seen from FIG. 12 (being a highly schematic top view of theoptical module 606.1 similar to the view of FIG. 3) the aperture stop609 is formed by a plurality of planar aperture elements 609.30 to609.34 which are rotatably supported on the support structure 110. Thecircular aperture element 609.30 and the annular aperture elements609.31 to 609.34 are arranged to be concentric to the axis of rotationof the aperture stop 609. Each one of the aperture elements 609.30 to609.34 supports the adjacent more inward one of the aperture elements609.30 to 609.34.

Each aperture element 609.30 to 609.34 includes a plurality of recessesin the form of slots 609.23 extending through the aperture element 609.2and forming a passageway for light passing the aperture stop 609. Eachof the slots 609.23 is associated to one of the spatially confinedsub-bundles 516.1 of the bundle 516 of rays of light provided by thelight source of the illumination unit 102.1. The sub-bundles 516.1 areevenly distributed and separated by non-irradiated areas as it has beendescribed above.

In the circumferential direction 617 of the aperture stop, the slotshave an arcuate design which is substantially concentric to the axis ofrotation of the aperture stop 609. This axis of rotation of the aperturestop 609 may coincide with the optical axis 101.1. However, with otherembodiments of the disclosure, any other suitable and desiredorientation of the axis of rotation of the aperture stop with respect tothe optical axis 101.1 may be chosen.

Under the control of a control unit 609.19, each aperture element 609.30to 609.34 may be individually driven (clockwise and counterclockwise)along the circumferential direction 617 via an associated drive unit609.24 and 609.35 to 609.38 connected to the control unit 609.19 andsupported on the adjacent more outward one of the aperture elements609.30 to 609.34 and the support structure 110, respectively. In thestate shown in FIG. 12 the slots 609.23 of the aperture element 609.2are arranged such that none of the sub-bundles 516.1 is blocked by theaperture element 609.2, i.e. all the sub-bundles 516.1 of the bundle 516can pass the aperture element 609.2 in their direction of propagation.

It will be appreciated that the aperture elements 609.30 to 609.34 maybe individually driven to provide any desired annular or circular shapeof the aperture 609.1. In particular, also multiple annular shapes ofthe aperture 609.1 may be provided.

It will be appreciated that, with this embodiment as well, in therespective state, the support to the respective parts of the apertureelements 609.30 to 609.34 does not obstruct the path of the exposurelight through the aperture 609.1 such that no loss in radiant power iscaused by the support to the respective parts of the aperture element609.30 to 609.34. Furthermore, this embodiment provides a very simplepossibility to selectively modify the geometry of the aperture withouthaving to move large masses along a complicated trajectory. Instead,only a simple rotation is involved to modify the geometry of theaperture 609.1. This solution provides very short reaction times forchanges in the setting of the aperture since only a small angle ofrotation may be sufficient to provide a change to the desired setting.

It will be further appreciated that the aperture slots 609.23 may bearranged and designed such that they provide virtually any desiredgeometry of the aperture 609.1. Furthermore, it will be appreciated thatthe aperture element 609.2 may be used in connection with any desiredoptical element. In other words, this solution is not limited to animplementation in connection with the segmented mirror 111 as it hasbeen described above. Rather any type of optical element may beassociated to the aperture element 609.2.

Furthermore, since the aperture element 609.2 does not necessitate anysupport apart from a support at its outer circumference, it is notnecessary to provide a close spatial relation between the apertureelement 609.2 and an optical element. Rather, the optical module 606.1may only include the aperture element 609.2 and no optical elementsupported by the support structure of the aperture element 609.2. Inthis case, obviously, the support structure of the aperture element609.2 may have an annular design not obstructing the part of the lightpassing the aperture element 609.2. In particular, the aperture element609.21 may for example be used in the optical module 108 of the opticalprojection unit 103 of FIG. 1.

In the foregoing, the disclosure has been described in the context of aplurality of embodiments where a first and a second aperture elementwere used to shape a bundle of light. It will be appreciated in thiscontext that, with the other embodiments of the disclosure, an arbitrarynumber of further aperture elements may be used in addition to thisfirst and second aperture element in order to shape a bundle of light.In particular, by this approach, the aperture may be provided with ageometry having a plurality of inner contours such as it is the case forexample for a bipole or quadrupole annular setting.

In the foregoing, the disclosure has been described in the context ofembodiments where the optical module according to the disclosure is usedin the illumination unit. However, it will be appreciated that theoptical module according to the disclosure may provide its beneficialeffects as well in the optical projection unit.

In the foregoing, the disclosure has been described in the context ofembodiments working in the EUV range. However, it will be appreciatedthat the disclosure may also be used at any other wavelength of theexposure light, e.g. in systems working at 193 nm etc.

Although, in the foregoing, the disclosure has been described solely inthe context of microlithography systems. However, it will be appreciatedthat the disclosure may also be used in the context of any other opticaldevice using aperture devices.

1.-20. (canceled)
 21. An optical module, comprising: an aperture device,comprising: an inner aperture element; an outer aperture element; and asupport element connecting the inner and outer aperture elements:wherein: the inner and outer aperture elements define a ring-shapedopening in the aperture device configured so that, during use of theoptical module, a first portion of light which impinges on the aperturedevice is blocked by the aperture device and a second portion of lightwhich impinges on the aperture device passes through the ring-shapedopening of the aperture device; the support bridges the ring-shapedopening; and the support element comprises a section-wise curved and asection-wise angled configuration to avoid loss of radiant power vialight impinging on the support element during use of the optical module.22. The optical module of claim 21, wherein the support elementcomprises a plurality of generally honeycomb-shaped sections.
 23. Theoptical module of claim 22, further comprising an optical elementspatially associated to the aperture device, wherein the optical elementcomprises a plurality of spatially separated sub-elements, and each ofthe honeycomb-shaped sections is functionally associated to one of thesub-elements.
 24. The optical module of claim 21, wherein the supportelement is releasably connected to the first aperture element and/or thesecond aperture element.
 25. The optical module of claim 21, wherein thesupport element is monolithically connected to the first apertureelement and/or the second aperture element.
 26. The optical module ofclaim 21, wherein: the aperture device is configured to cooperate withlight comprising a plurality of spatially confined sub-bundles separatedby a non-irradiated area; the non-irradiated area is not irradiate bythe light; and the support element is configured to exclusively extendwithin the non-irradiated area.
 27. The optical module of claim 26,wherein the support element comprises a plurality of generallyhoneycomb-shaped sections, and each of the honeycomb-shaped sections isassociated to one of the spatially confined sub-bundles.
 28. The opticalmodule of claim 21, further comprising an optical element unit aplurality of optical elements located adjacent to the aperture devicewherein the inner aperture element and/or the outer aperture element issupported on the optical element unit to shield at least a part of anoptically used surface of one of the optical elements from light whenbeing supported on the optical element unit.
 29. An optical module,comprising: an aperture device comprising a plurality of apertureelements, defining an opening in the aperture device configured so that,during use of the optical module, a first portion of light impinging onthe aperture device is blocked by the aperture device and a secondportion of light impinging on the aperture device passes through theopening of the aperture device, wherein: the plurality of apertureelements define a geometry comprises a first aperture element and asecond aperture element; the aperture device is configured to modify ageometry of the opening of the aperture device by adjusting the firstaperture element from a first state to a second state to independentlymodify a position and/or an orientation of the first aperture elementwith respect to the second aperture element to modify the geometry ofthe aperture; in the first state of the first aperture element, thefirst and second aperture elements define a first geometry the openingof the aperture device; in the second state of the first apertureelement, the first and second aperture elements define a second geometrythe opening of the aperture device; and the second geometry is differentfrom the first geometry.
 30. The optical module of claim 29, wherein thefirst aperture element is a movable element, and a position and/or anorientation of the first aperture element is altered when the firstaperture element is adjusted between the first and second states. 31.The optical module of claim 30, further comprising an optical elementunit comprising an optical element adjacent to the first apertureelement, wherein: in the first state of the first aperture element, thefirst aperture element is configured to shield at least a part of anoptically used surface of the optical element from incident lightpropagating along a line of propagation; the first aperture element hasa recess; and in the second state of the first aperture element, therecess is configured so that the incident light propagating along theline of propagation impinges the part of the optically used surfaceshielded in the first state.
 32. The optical module of claim 29, whereinthe first aperture element is a deformable element, and the firstaperture element undergoes a deformation when being transferred betweenits first and second states.
 33. The optical module of claim 32, whereinthe first aperture element comprises an active element configured toinduce at least a part of the deformation of the first aperture elementwhen subject to at least one field selected from the group consisting ofan electric field, a magnetic field and a thermal field.
 34. The opticalmodule of claim 29, further comprising an optical element unitcomprising an optical element located adjacent to the first apertureelement, wherein: the first aperture element is supported by the opticalelement unit; and in its first state, the first aperture element shieldsat least a part of an optically used surface of the optical element fromincident light.
 35. The optical module of claim 34, wherein: the opticalelement unit comprises a plurality of optical elements and a supportstructure supporting the plurality of optical elements; the firstaperture element is supported by the support structure; and in its firststate and/or its second state, the first aperture element extends in agap between two of the optical elements.
 36. The optical module of claim35, wherein: the support structure comprises a receptacle locatedadjacent to the optical element; and in its second state, the firstaperture element is in a retracted state in which the first apertureelement is at least partly received within the receptacle.
 37. Theoptical module of claim 29, wherein the optical module comprises aplurality of the first aperture elements.
 38. The optical module ofclaim 29, wherein the plurality of aperture elements define a ringshaped geometry of the opening of the aperture.
 39. A method,comprising: providing a bundle of light and a plurality of apertureelements, the plurality of aperture elements defining an opening in anaperture device configured so that a first portion of the bundle oflight impinging on the aperture device is blocked by the aperture deviceand a second portion of the bundle of light impinging on the aperturedevice passes through the opening of the aperture device, the pluralityof aperture elements comprising a first aperture element and a secondaperture element; shaping the bundle of light using the aperture device;modifying the geometry of the opening of the aperture device bytransferring the first aperture element from a first state to a secondstate by independently modifying a position and/or an orientation of thefirst aperture element with respect to the second aperture element,wherein: in the first state of the first aperture element, the first andsecond aperture elements define a first geometry the opening of theaperture device; in the second state of the first aperture element, thefirst and second aperture elements define a second geometry the openingof the aperture device; and the second geometry is different from thefirst geometry.
 40. An optical module, comprising: an aperture devicecomprising a plurality of aperture elements defining an opening in theaperture device configured so that, during use of the optical module, afirst portion of light impinging on the aperture device is blocked bythe aperture device and a second portion of light impinging on theaperture device passes through the opening of the aperture device,wherein: the plurality of aperture elements comprise a first apertureelement and a second aperture element defining a ring shaped geometry ofthe opening of the aperture device; in a state of the aperture device,the first aperture element defines an inner contour of an aperturehaving a the ring shaped geometry; in the state of the aperture device,the second aperture element defines an outer contour of the ring shapedgeometry aperture; in the state of the aperture device, the aperture isconfigured adapted to be passed by a defined bundle of rays of exposurelight forming the second portion of exposure light; and the firstaperture element is supported so that a path of the bundle of rays ofexposure light through the opening of the aperture device is at leastsubstantially not unobstructed, so that the second portion of exposurelight at least substantially corresponds to a total amount of exposurelight impinging on the ring shaped geometry.
 41. The optical module ofclaim 40, wherein: the defined bundle of rays of light has a definedaverage radiant power per area in a direction of radiation; in a planeperpendicular to the direction of radiation, the inner and outercontours define a ring-shaped surface having an area; and the firstaperture element is supported so that a radiant power of the definedbundle of rays of light passing the opening of the aperture device inthe direction of radiation corresponds to a product of an averageradiant power per area and the defined area of the ring-shaped surface.42. The optical module of claim 40, wherein: the defined bundle of raysof light comprises a plurality of spatially confined sub-bundlesseparated by a non-irradiated area; the non-irradiated area is notirradiated by the defined bundle of rays of light; the first apertureelement is supported by a support structure; and the support structuredoes not interfere with the sub-bundles and/or the support structurecomprises a support element extending through the non-irradiated area.43. The optical module of claim 42, wherein the support structurecomprises a support element extending through the non-irradiated area.44. The optical module of claim 43, wherein said support elementcomprises a strut element.
 45. The optical module of claim 43, whereinsaid support element comprises a plurality of generally honeycomb-shapedsections.
 46. The optical module of claim 45, wherein at least one ofsaid sub-bundles passes through an interior of one of said generallyhoneycomb-shaped sections without interfering with said honeycomb-shapedsection.
 47. The optical module of claim 43, wherein the support elementis releasably connected to the second aperture element, and/or thesupport element is monolithically connected to the second apertureelement.
 48. The optical module of claim 40, further comprising anoptical element unit comprising a plurality of an optical elementslocated adjacent to the aperture device, wherein the first apertureelement and/or the second aperture element is supported on the opticalelement unit and shields at least a part of an optically used surface ofone of the optical elements from incident light when being supported onthe optical element unit.
 49. The optical module of claim 48, whereinthe optical element unit comprises a support structure supporting theoptical element, the first aperture element and/or the second apertureelement is supported on the support structure via a support deviceand/or is locked in position with respect to the support structure via alocking device.
 50. The optical module of claim 49, wherein the opticalelement unit comprises a plurality of optical elements, the supportstructure supports the plurality of optical elements, and the firstaperture element is supported on the support structure via a supportelement extending in a gap between two of the optical elements.
 51. Anarrangement, comprising: an illumination unit configured to illuminatean object; and an optical projection unit configured to transfer animage of the object onto a substrate, wherein the illumination unitand/or the projection optical unit comprises an optical module accordingto claim
 21. 52. The arrangement of claim 51, wherein: the illuminationunit is adapted to illuminate the object via a plurality of separatespatially confined bundles of rays of light separated by anon-irradiated area; the non-irradiated area is not irradiated by saidbundles of rays of light; and the aperture device is configured toselectively modify a geometry of the aperture to prevent at least one ofthe bundles of rays of light from reaching the substrate.
 53. Thearrangement of claim 51, wherein: the first aperture element and/or saidsecond aperture element is a movable aperture element adapted to betransferred from a first state to a second state; in the first state,the aperture has a first geometry; in the second state, the aperture hasa second geometry different from the first geometry; and a positionand/or an orientation of the movable aperture element is altered whenthe movable aperture element is transferred between the first and secondstates.